Asthma has consistently been reported as a major cause of chronic cough. The development of noninvasive assessment of airway inflammation led to the identification of a condition that manifests chronic cough in individuals without the abnormalities of airway function that characterize asthma, but with sputum eosinophilia. This condition was named nonasthmatic eosinophilic bronchitis (NAEB). The reason for the absence of airway hyperresponsiveness in the NAEB remains unclear. Inflammation of the airways, with recruitment and activation of T lymphocytes, eosinophils, and mast cells and release of inflammatory mediators, plays an important role in the pathophysiology of asthma and NAEB. Among lipid mediators, PGE2 is a mediator thought to have an important role.
The accumulation of Eosinophilic bronchitis is a common cause of chronic cough, which like asthma is characterized by sputum eosinophilia, but unlike asthma there is no variable airflow obstruction or airway hyperresponsiveness. Several studies suggest that prostaglandins may play an important role in orchestrating interactions between different cells in several inflammatory diseases such as asthma. PGE2 is important because of the multiplicity of its effects on immune response in respiratory diseases; however, respiratory system appears to be unique in that PGE2 has beneficial effects. The difference in airway function observed in patients with eosinophilic bronchitis and asthma could be due to differences in PGE2 production. PGE2 present in induced sputum supernatant from NAEB patients decreases BSMC proliferation, probably due to simultaneous stimulation of EP2 and EP4 receptors with inhibitory activity. This protective effect of PGE2 may not only be the result of a direct action exerted on airway smooth-muscle proliferation but may also be attributable to the other anti-inflammatory actions.
Managing acute pathology of often relies on the addressing underlying pathology and symptoms of the disease. There is currently a need in the art for new compositions to treatment of asthma and allergy.